F5 APM SSLVPN unstable connection

We are currently using F5 BIG-IP 2000 APM with version 14.0.0.1 for SSLVPN and we are facing the unstable connection. In our environment, we are using Windows7 and Windows10 devices. In operation, we access the VPN through the web browser. All the Windows7 device can access and connect normally. However, for those Windows10 devices, the connection is not stable. Those Windows device sometimes can access and connect but sometimes they cannot.

In normal practice, when the user accesses the website to access the VPN, the browser will prompt out a notification to request the user to download, install and run the Endpoint Inspection Client. After the installation complete and run the application, a security certificate alert message will be prompted out. The VPN will be connected after we accept the alert. However, the security alert is not always prompt out. The web browser just keeps staying in the page that waiting for Endpoint Inspection status. We have tried to delete and reinstall the Endpoint Inspector client but the same issue still happened.

We checked the debug log in the APM but there are no finding for this. What information should i collect and what is the possibe cause for this unstable connection?

Thanks, Remus